1. Field of the Invention
The present invention relates to a display system and an electrical appliance capable of brightness control based on information on surroundings.
2. Description of the Related Art
In recent years, the development of display devices using electro luminescent (EL) elements (hereinafter referred to as EL display device) has been advanced. EL elements are of self-light-emitting type devised by utilizing the phenomena of electro luminescence (including fluorescence and phosphorescence) from organic EL materials. Since EL display devices are of a self-light-emitting type, they require no backlight such as that for liquid crystal display devices and have a large viewing angle. For this reason, EL display devices are regarded as a promising display portion for use in portable devices used outdoors.
There are two types of EL display devices: a passive type (simple matrix type) and an active type (active matrix type). The development of either type of EL display devices is being promoted. In particular, active matrix EL display devices are presently receiving attention. Organic materials for forming light-emitting layers of EL elements are grouped into low-molecular (monomeric) organic EL materials and high-molecular (polymeric) organic EL materials. Studies of these kinds of materials are being actively made.
None of EL display devices and light-emitting devices including semiconductor diodes, heretofore known, has any function of controlling the luminance of a light-emitting element in the light-emitting device based on information on surroundings of the light-emitting device.